European ST-T Database

Use of downloaded data from this database is permitted for research and
not for commercial use (i.e., testing commercial equipment for quality
assessment according to ANSI-AAMI recommendations or other standards).

For commercial use, obtain the European ST-T Database CD-ROM (write to Alessandro Taddei
<taddei@ftgm.it> for further information).

The European ST-T Database is intended to be used for evaluation of algorithms
for analysis of ST and T-wave changes. This database consists of 90 annotated
excerpts of ambulatory ECG recordings from 79 subjects. The subjects were 70
men aged 30 to 84, and 8 women aged 55 to 71. (Information is missing for one
subject. Records e0118-e0122 come from the same subject; also records
e0123-e0126, records e0129 and e0133, records e0136 and e0139, records e0147
and e0148, records e0154 and e0155, and records e0162 and e0163.) Myocardial
ischemia was diagnosed or suspected for each subject (see reference 1);
additional selection criteria were established in order to obtain a
representative selection of ECG abnormalities in the database, including
baseline ST segment displacement resulting from conditions such as
hypertension, ventricular dyskinesia, and effects of medication. The database
includes 367 episodes of ST segment change, and 401 episodes of T-wave change,
with durations ranging from 30 seconds to several minutes, and peak
displacements ranging from 100 microvolts to more than one millivolt. In
addition, 11 episodes of axis shift resulting in apparent ST change, and 10
episodes of axis shift resulting in apparent T-wave change, have been marked.
Compact clinical reports document each record. These reports, contained within
the header (.hea) files associated with each record, summarize
pathology, medications, electrolyte imbalance, and techical information about
each recording.

Each record is two hours in duration and contains two signals, each sampled at
250 samples per second with 12-bit resolution over a nominal 20 millivolt input
range. The sample values were rescaled after digitization with reference to
calibration signals in the original analog recordings, in order to obtain a
uniform scale of 200 ADC units per millivolt for all signals. (The calibration
signals are not included in the signal files.) The header files include
information about the leads used, the patient's age, sex, and medications, the
clinical findings, and the recording equipment. Each of the signal files is
5,400,000 bytes long.

Two cardiologists worked independently to annotate each record beat-by-beat and
for changes in ST segment and T-wave morphology, rhythm, and signal quality.
ST segment and T-wave changes were identified in both leads (using predefined
criteria which were applied uniformily in all cases), and their onsets,
extrema, and ends were annotated. Annotations made by the two cardiologists
were compared, disagreements were resolved by the coordinating group in Pisa
(see reference 3), and the reference annotation files were prepared;
altogether, these files contain 802,866 annotations. A detailed description
of the annotations may be found here.

Over half (48 of 90 complete records, and reference annotation files for all
records) of this database was contributed to PhysioNet in 2000, and the
remainder was contributed in November 2009. A list of all 90
record names is available here.

Acknowledgements

We thank Carlo Marchesi, Alessandro Taddei, and Michele Emdin of the CNR
Institute for Clinical Physiology in Pisa for arranging for these recordings to
be made available via PhysioNet. Our thanks also to Maarten L. Simoons, Simon
Meij, and Johan H.C. Reiber, and to the European Society of Cardiology and its
Working Group "Computers in Cardiology", for their support.